Performance evaluation of a transformerless multiphase electric submersible pump system

Abstract

Using of low‐voltage variable‐frequency drive followed by a step‐up transformer is the most preferable way to feed an electrical submersible pump motor. The existence of long feeder between the motor and drive systems usually causes over‐voltage problems because of the travelling wave phenomenon, which makes the employment of filter networks on the motor or inverter terminals mandatory. The so‐called boost‐inverter inherently can solve this problem with filter‐less operation as it offers a direct sinusoidal output voltage. As boost inverters have voltage boosting capability, it can provide a transformer‐less operation as well. This study investigates the performance of a five‐phase modular winding induction machine fed from a boost‐inverter through a long feeder. A simulation study using a 1000 Hp system and experimental investigation on a 1 Hp prototype machine are used to support the presented approach.